"The self-checking Subtraction Machine makes math so simple, kids can teach themselves. Children just press the operation buttons?and the answers pop up for immediate reinforcement. 81 equation buttons lock securely into the tough 8 1/2" x 9 1/2" plastic frame." PLEASE REFER TO THE INCLUDED PICTURES IN ORDER TO UNDERSTAND EXACTLY WHAT YOU WILL BE PURCHASING. No returns and/or refunds. If you have any comments or concerns, please contact the seller before leaving negative feedback. International shipping is not an option. Shipping charges are based, in part, on the buyer's location. Buyer pays actual shipping costs. Seller is responsible for all handling fees. Customer Service is a PRIORITY for this seller! Have any questions? Don't hesitate to ask. Anxious to do business .... Thanks for viewing and/or considering this listing.